and i was told to just sync my iphone to itunes to get the latest iOS version but i was hesitant because i heard and i knew that since its been jailbreak, you cant just sync it normally to the itunes for it will cause incompatibilities and such problems.

I went and followed what the moderator said. Since i felt that its reassuring.

It failed drastically and now my phone is back to being locked and the phone doesnt recognize my sim.

Your baseband has been updated to 05.16.xx which locks you back to official carrier.
To unlock you run redsn0w 0.9.15b3 and choose the ipad baseband update (6.15.00)
Once you have done that, run redsn0w again and choose the downgrade baseband ( 05.13.xx)
Now you are at 6.0.1 with baseband 05.13.xx.
To unlock you need to jailbreak with Redsn0w.
Once jailbroken, install Ultrasn0w and Ultrasn0w fixer by adding this repo to Cydia : repo.iparelhos.com.
If successful, your iphone is now unlocked for GSM carriers.

If your iphone is new bootrom, then it will be a tethered jailbreak meaning you need a computer and redsn0w to boot up your iphone if you ever power down.